Those characters were included in the original Fantastic Four rights, so that's not a shocker. Galactus and Silver Surfer were two characters Marvel tried to bargain back separately and were turned down.The Galactus, Surfer and Doom bit is an update. Still only a rumour, but what else could Fox have offered Marvel ?
What else could Fox have offered Marvel? You mean to use the TV rights? How about a bunch of cash? The rights were being unused because neither side could use them without permission. As long as you don't make the deal in perpetuity like Marvel did for the film rights, it makes some sense to make a business deal happen to richen both sides.